Casting machine



Get. 2 ,1923. E,469,28

L. A. STORZ CASTING MACHINE Filed Nov. 1, 1920 Plasma/9E PPESSUPE /Di eon H. S72v2 Pawnee ca. 2, i923.

entree areas meager LEON A. STOBZ, OF WORCESTER, MASSACHUSETTS.

CASTING MACHIITE.

Application filed November 1, 1920. Serial No; 421,120.

To all whom it may concern:

Be it known that 1, Leon A. STORZ, a citizen of the United States, residing at Worcester, in the 'county of Worcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in a Casting Machine, of which the following, together with the accompanying drawings, is a specification.

My invention relates to metal casting machines, particularly of the type employed by dentists for the casting of inlays, bridges, plates, and the like, in which a source .0 pressure is employed in connection with the casting operation to force the molten metal into the mold. It is to be understood, however, that my machine is capable of application to other classes of work which may require the formation of relatively small metal castings.

In In copending application Serial No. 379,296, filed May 6, 1920, there is shown and described a casting machine of the above mentioned type, in which a vertically movable flask containing a mold is adapted to operate a valve mechanism located above the flask. The valve mechanism controls the flow of fuel and pressure mediums through a nozzle in the direction of the flask, so that the metal which is to be cast is first melted and then subjected to pressure.

The object of the present invention is to provide a castingmachine embodying the essential elements of the machine described in the above mentioned copending application withcertain improvements, whereby its eiiectiveness in 'operation is greatly increased. My improved machine is also universal in its application, in that it may utilize any available sources of'fuel and pressure in various combinations without necessitating any changes in its general arrangement. These and other advantageous features of my invention will hereinafter more fully appear, reference being had to the accompanying drawings, in which- Fig. 1 is a view, partially in section, of my improved casting machine.

Fig. 2 is a sectional view along theline 22 of Fig. 1.

Fig. 3 is asectional view similar to Fig. 2, showing the machine connected for operation with a difierent fuel supply from'that shown in Fig. 2.

Like reference characters refer to like parts in the different figures.

Referring to the drawings, the machine generally comprises a base 1 provided with an upwardly extending standard 2, which terminates in a cylindrical portion 3 overhanging the base 1. A cylinder 4 is mounted on'the base 1 and a piston 5 is adapted to operate therein. A plunger 6 is connected to the piston 5 at its lower end and at its upper end extends through the top of the cylinder 4, Where it is connected to a castf ing table 7. The table? is provided with a number of concentric depressions or seats 8, within one of which is received a hollow cylindrical flask 9. The flask 9 is filled with investment material 10, and a mold, as indicated at 11, is formed therein by any suitable means. .A convex depression 12 is provided in the material 10 and is in communication'with the mold 11 through a sprue way 13. A quantity of metal 14 is located in the depression 12 and is adapted to be melted by instrumentalities which will be hereinafter described.

The inner wall of the flask 9 is provided with a peripheral groove 15, into which the investment material 10 enters when it is placed in the flask 9. The bottom of the flask 9 is provided with a plurality of open.- ings 16, which are in communication with an axial and radial passage 17 provided in the plunger 6. The functions of the groove 15 and of the openings 16 during the opera-.

tion of the machine will be hereinafter more fully described.

The cylinder 4 is provided at its ends with ports 18 and 19. which are connected by piping to a suitable two-way valve 20. The valve 20 may be of any usual construction, so that its inlet port 21 will be connected to one port 18 of thecylinder 4: when its exhaust port 22 is connected to theother 19 of the cylinder 4, and vice versa. The inlet port 21 of the valve20 is connected to a suitable source of air under pressure through a suitable air filter, as indicated at 23. The filter 23 maybe of any usual type in which air under pressure is forced to pass through some material which removes the moisture therefrom, provision "being made port for the removal of the moisture by means lower end of the" cyliinder 4, but it is obvious that should the valve 20 be turned through i portion 3 of the standard 2 is provided with a central longitudinal opening 25, within which valve members 26 and 27 are adapted to slide. The upper valve member 26 is provided with a central passage 28, which communicates with a radial passage 29 extending to the outer periphery of the valve member. A pipe 30, terminating in a restricted opening or jet 31, is secured in the passage 28 and extends downwardlyfrom the valve member 26 into a central opening 32 provided in the lower valve member 27, the opening 32 being considerably larger in diameter than the pipe 30, for a purpose to be hereinafter described.

The upper valve member 26 is further provided with spaced peripheral grooves 33 and 34 that are adapted to seat a ball 35, forced inwardly toward the member 26 by means of a s ring 36. When the ball 35 is seated in the ibwer groove 34, the valve member 26 is maintained in the position shown in Fig. 1. The valve member 26 is also provided with an enlarged head 37, by means of which the member 26 may be depressed until the ball 35 is seated in the upper groove 33. When the valve member 26 is depressed, the radial passage 29 is brought into register with a port 38 to which is connected a supply pipe 39. The supply pipe 39 is connected to a suitable source of fuel under pressure, which, as indicated in Fig. 1, maybe a tank 40 mounted on the base 1. The tank 40 may contain suitable combustible gas such, for example, as oxygen, under considerable pressure, which may be used in combination with another combustible gas'such as ordinary illuminating gas, not under an appreciable pressure, by

connecting both sources to the pipe- 39, as indicated in Fig. 1. A suitable valve 41 is providedat the to of the tank 40 for controlling thefiow o the pressure medium Etc the supply pipe 39.

The lower valve member 27 is provided at its lower end with a plate 42 having a,

plurality of concentric packing rings 43, which correspond in diameter to the seats 8 provided in the casting table 7. A spring 44 surrounds the valve member between the plate 42 and the end of the cylindrical portion ,3, and maintains an en larged portion 45 of the. valve member in engagement with a shoulder 46 provided on the cylindrical portion 3. The plate 42 is provided'with upwardly extending steps 47 which are adapted to limit eeaeea opening 32, to register with a port 49 provided in the cylindrical portion 3. The port 49 is connected to a supply pipe 50 which, as best shown in Fig. 1, is connected to a source of air under premure above the valve 20.

Having thus described the various parts entering into my invention, the operation thereof is as follows :--'The mold 11 having been formed in the flask 9 in any suitable manner, a suflicient quantity of metal 14 is then placed in the depression 12 and the flask 9 is positioned on the table 7. The head 37 of the upper valve member 26 is then depressed thus bringing the pipe 30 into communication with the source of fuel under pressure, the valve member 26 being held in this position by the ball 35 engaging inthe groove 33.- The gases are thoroughly mixed in the pipes 30 and 39 before passing through the jet 31 where they are ignited. The metal14-is heated b the flame thus produced until it reaches t e desired molten condition preparatory to forming the casting. The amount of heat to which the metal is subjected is readily controllable by raising or lowering the table 7 through manipulation of the valve 20. When the metal 14 has reached the desired molten state, the valve 20 is operated to. cause the piston 5 to be moved upwardly to the end of its stroke, thereby raising the flask 9 until the top'engages the plate 42. Continued upward movement of the table 7 causes the lower. valve member 27 to be moved upwardly until the stops 47 engage the bottom of the cylindrical portion 3. The upper valve member 26 moves with the lower valve member, thereby causing the radial passage 29 to be moved outof register with the port 38. This immediately cuts oil the flame at thejet 31, and at lmost the same instant, the radial passage 48 registers with the port 49, thereby admitting air under pressure 'to the opening 32 surrounding the flame pipe 30. The molten metal 14 is then subjected to pressure over substantially its entire surface and is forced through the sprue-way 13 into the mold 11. The pres-- sure is held between the plate 42 and the upper edge of the flask 9 by means of one of the packing rings 43, which is pressed against the flask by means of the spring 44, the other packing rings 43-providing a. seal when flasks of greater or of less diameter are employed. The metal 14 is subjectedto pressure for a suflicient time to allow the casting to form within the mold 11. During the casting operation the entire top surface of the investment material 10 is subjected to premure so that a certain amount of air finds its way through meaaee the porous material. The openings 16 in the bottom of the flask 9 provide a large number of outlets for the air to the passa e 17 in the plunger 6, so that there is no ten ency for the investment material to be moved within the flask 9, due to excessive air pressure. This might otherwise occur were the bottom of the .flask to be provided with a single opening as in previous constructions. The groove 15 also. provides a secure anchor 101? the investment material, so that there is but little chance of the mold 11 being spoiled by movement of the investment material during the casting operation. After the casting is complete, the table 7 is lowered by admitting air to the upper port 18 of thecylinder 4 so that the flask may be removed. The lowering of, the table 7 permits the spring 44 to move the valve member 27 to its :lower position, thereby cutting ofl the pressure. The valve member 26 is normally held in its u per position with the fuel shut ofl' by t e ball 35 seated in the lower groove 34:.

My improved machine is readily adapted for operation where fuel only under ordinary pressure is available by a very simple change, illustrated in Fig. 3. A casing 51, of greater inside diameter than the pipe 30, is secured in a countersunk portion 52 of the passage 28 in the valve member 26. The casing 51 extends downwardly into the opening 32 in the lower valve member 27 and is constructed at its lower end, as shown at 53, to partially inclose the jet 31, a space being left. between the end of the casing 51 and the tip of the jet. A radial duct 54 communicates with the countersunk portion 52 and is adapted to register with a port 55 when the valve member 26 is depressed to seat'the ball 35 in the upper groove 33. A pipe 56 leads from the ort 55 to asuitable source of fuel under ordinary pressure. The pipe 39, leading from the port 38, is connected to a source of air under pressure, so

that when the valve member 26 is depressed, the air discharging from the jet 31 will draw the fuel through the casing 51. When the fuel is ignited, the'device will operate as a blow-torch to project an intense flame in the direction of the flask 9. The pipe 50 is connected to a source of air under pressure as before, and the operation of the machine is substantially the same as described with reference to Fig. 2.

From the foregoing, it is apparent that I have provided an improved casting machine that is adapted to successfully. operate with diflerent combinations of fuel mediums, without necessitating any material changes in the parts of the machine. My machine is also-extremely eflective in, its operation, owing to the rovision of the pressure operated casting tab e. It is possibleto maintain the flask any desired distance from the source of the flame while the metal is being melted and to hold the flask in contact with the plate 42 with a steady pressure during the.

casting operation. The provision of a relatively lar e free opening in the lower valve member t rough which the pressure is applied to the flask, insures that a considerable area of the molten metal will be exposed to the ressure. This prevents the molten metal rom being blown out of the depression 12 as might readily occur should the pressure medium be discharged through a restricted opening, such as the jet 31. The provision of a plurality of openings at the bottom of the flask permits the ready relief of the air which finds its way through the investment material, without any tendency for the material to be moved within the ile I have shown my present invention embodied in a casting machine operated on the same general principles as the machine class described, the

described in my above described copending' tion of the valve mechanism to operate said mechanism.

2. In a machine of the class described, the {combination with a standard carrying a valve mechanism, of a casting table mounted on a pressure operated piston movable within a cylinder located below the valve mechamam.

3.. In a machine of the class described, the combination with a source of pressure and a standard carrying a valve mechanism, of a casting table mounted on a iston movable within a cylinder locate below the valve mechanism, and means for controlling the movement of the piston within the cylinder by its connection to said pressure source.

d. In a machine of the class described, the combination with a casting table mounted on aplunger connected to a piston movable within a closed cylinder, of a flask carried on said table and adapted to be subjected to a pressure medium, the said flask and the said plunger being provided with openings for the escape of the ressure medium from sald flask when the sald flask is in its upper position.

5. In a machine of the class described, the combination with a casting table mounted on a plunger connected to a. piston movable 1 within a cylinder, and a valve mechanism forv controlling the flow of a pressure medium in thedirection of said table, ot a flask carried on said table and adapted to be subjected to the pressure medium upon operation of said valve mechanism by movement of said table, the bottom of said flask being provided with openings, and the said plunger being-provided with a duct for the escape of the pressure medium from said flask when the piston is near the top of said cylinder; v a

6. In a machine of the class described, the

combination with a movable table, a source of fuel and a source of pressure, of a valve mechanism comprising valve members relatively movable in the same directionas said table and provided with coaxial passages for the separate flow of fuel and pressure mediums in the direction of said table.

7 In a machine of the class described, the

combination with amovable table, a source mechanism operable by the movement of said table and comprising a valve member incenseprovided with a passage having a restricted opening for connection to the source of fuel and another valve member provided with a passage having a free opening for connection to the source of pressure.

9. In a machine of the class described, the combination with a'movable table, a source or fuel and a source of pressure, of a valve mechanism operable by movement of said table and comprising a valve member having a constricted passage for connection to said source of fuel, and another valve member having a passage of substantially the same cross section throughout its length for connection to said source of pressure, the said passages being coaxial.

10. In a machine of the class described, the combination with a vertically movable flask for receiving a mold, a source of fuel and a source of pressure, of a valve mechanism connected to said sources and adapted to discharge fuel medium through a con stricted passage and to discharge pressure medium through'a free passage in the direction of said flask.

11. In a machineof the class described,

the combination with a vertically movable flask for receiving a mold, a source of fuel and a source of pressure, of a valve mechanism connected to said sources and comprising a valve member provided with a pipe terminating in a restricted opening for t e discharge of fuel medium and another valve member provided with a free passage for the discharge of pressure medium.

- 1 LEON A. STORZ. 

